I've lost the ref to a quote. If it's yours, or you recognize it, please
let me know.
Thanks, -Dick Gordon
"In the original formulations of gradients in the insect segment (Stumpf,
1966; Lawrence, 1966), the pattern of differentiation and the orientation
of structures such as bristles and hairs were believed to be separate
manifestations of the same underlying gradient.... However, patterns of
differentiation and of polarity can be affected separately in mutants of
Drosophila (Gubb & Garc=EDa-Bellido, 1982; Held Jr., Duarte & Derakhshanian=
,
1986) and can be dissociated in rotated cuticular grafts in the bug
Dysdercus (N=FCbler-Jung & Grau, 1987; N=FCbler-Jung, 1987).... The polarit=
y
pattern is strictly dependent on local cell-to-cell interactions, possibly
related to concordance in orientation of microtubule organizing centers
(Whitten, 1973; N=FCbler-Jung, Bonitz & Sonnenschein, 1987).... N=FCbler-Jun=
g,
Bonitz & Sonnenschein (1987) have compared the hierarchy of control in
Dysdercus to the situation encountered in janus Tetrahymena, in which
dissociation of local and global asymmetry was first reported
(Jerka-Dziadosz & Frankel, 1979)."
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Dr. Richard Gordon, Department of Radiology
University of Manitoba, Room ON104, Health Sciences Centre
820 Sherbrook Street, Winnipeg, MB R3A 1R9 Canada
Phone: (204) 789-3828, Fax: (204) 787-2080, Home: (204) 589-0411
E-mail: GordonR at cc.UManitoba.ca